Field of the Invention
This invention relates generally to hypodermic syringes, and more particularly, to a hypodermic syringe that is capable of use only once, and which has a part that is removable after use to serve as a needle guard.
It is frequently necessary to use hypodermic syringes for intravenous administration of fluids, or to withdraw fluids from the veins of a person during the course of treatment of an illness, or in routine diagnostic examinations. Hypodermic syringes used for this purpose are generally disposable, and are intended to be discarded after a single use by trained medical personnel.
Unless they are properly disposed of, these used syringes present a health hazard. One of the more serious concerns of health care workers is the danger of becoming accidentally infected with HIV-infected blood or other materials. Acquired Immune Deficiency Syndrome (AIDS) is now recognized as an epidemic of global proportion. In addition, there is an increasing recognition of a broad spectrum of severe HIV-associated diseases, including pneumonia, endocarditis, and pulmonary tuberculosis. Medical and rescue personnel are aware of these risks, and when possible, take precautions to avoid unnecessary exposure or contact with infectious materials.
However, if a used syringe has been left intact and not properly disposed of, medical and rescue personnel, custodial workers, and others, are exposed to the danger of being accidentally pricked with the contaminated needle in spite of the precautions that they might normally take. Such a needle could be mingled with soiled linens, bandages or other materials, and when these materials are gathered for disposal, the needle has the distinct potential of penetrating the skin of anyone handling the materials.
The used syringe could also fall into the hands of a drug addict or other person who may be inclined to reuse the syringe. Such persons typically reuse a syringe many times and share it with other addicts. If the syringe has been used to make an injection or to withdraw body fluid from a person having an infectious disease, all of those persons subsequently using the contaminated needle are at risk of acquiring the infectious disease.
Intravenous drug use is believed to account for most AIDS-related diseases in heterosexual men and women. This disease may also be transmitted to the children of infected adults, and to the sex partners of the infected persons, or to others, such as medical workers and rescue personnel, who may be inadvertently exposed to the blood of the infected person.
As AIDS-related diseases continue to grow, it is becoming increasingly more important to control the means by which these diseases are transmitted. Medical personnel should have reasonable assurance that they can perform their procedures without unnecessary risk of exposure to such infectious diseases, and without requiring time-consuming steps to render used syringes safe for subsequent handling.
To prevent such accidents from occurring, the needles should be broken from the used syringes, and/or encased in a protective sheath, and devices have been provided in the prior art for accomplishing this. For instance, needles have been joined to the syringe body through frangible connections so that the doctor, nurse or other medical personnel can easily break the needle from the syringe after it is used. Unfortunately, this is not always done during the urgency of medical treatment, or if it is, there still remains an exposed needle body.
Similar shortcomings exist with respect to guards or sheaths that have been provided to encase the used needle. Such guards generally comprise separate sleeves or cap members that enclose the needle before it is used and which must be removed and set aside during use of the syringe. It is intended that after use of the needle, the guard will again be placed over the needle. However, the guard may become misplaced during the medical procedure being performed and therefore not available for reuse. Even if it is not misplaced, the person responsible for safe handling of the syringe may not have the time, or take the time, to retrieve the guard and place it over the needle. Further, even if such a conventional guard is placed on the needle, it is capable of being removed, whereby the syringe could again be rendered capable of use.
In addition to an effective needle guard for used syringes, a means is needed to prevent sharing and reuse of syringes by intravenous drug abusers, and thereby to prevent the spread of infectious diseases caused by use of contaminated syringes. Since the major cause of spread of HIV, Hepatitis and similar diseases is through the repeated and/or shared use of contaminated hypodermic syringes and needles, a significant preventive measure would be the elimination of the ability of intravenous drug abusers to acquire syringes that could be used more than one time.
Accordingly, it would be desirable to have a disposable hypodermic syringe that is reliable in operation, simple and economical in construction, and in which a part of the syringe assembly itself is adapted as a needle guard after the syringe has been used for its intended purpose. It would further be desirable to provide a disposable syringe that is not capable of being reused after a single use.